The collective posted a manifesto regarding "Operation Last Resort," along with a set of encrypted files that it claims have "enough fissile material for multiple warheads."

Anonymous won't specify the contents of the files at issue but said it would start leaking the documents, with heavy redactions, to one media outlet "at a regular interval commencing today," according to CNET.

Anonymous says it's avenging the death of Aaron Swartz, a 26-year-old Internet activist with a history of depression who killed himself on January 11. Many of Swartz's friends and colleagues have blamed his suicide on the U.S. Attorney's office in Massachusetts and its efforts to punish Swartz for illegally downloading millions of academic articles from a subscription database.

Anonymous still says Swartz was "killed" because he faced an "impossible choice."

Swartz died "because he was forced into playing a game he could not win – a twisted and distorted perversion of justice – a game where the only winning move was not to play," the group said.

Anonymous wants the feds to rethink sentencing guidelines and overhaul the Computer Fraud and Abuse Act, the mid-1980s law that's being used to prosecute modern-day hackers.

The encrypted files, which were named after each of the nine Supreme Court justices, can only be opened with an encryption key that Anonymous said it does not necessarily want to provide to its followers. It hopes to never have to "detonate" its "warhead."

The Sentencing Commission's site was down as of Monday around noon. On Sunday night, Anonymous compromised the site a second time, releasing a code that allowed users to turn the site into a game of Asteroids, ZDNet reports.

The USSC sets the sentencing guidelines for crimes tried in federal courts, and Anonymous said it chose the site for symbolic reasons.